CZ20033401A3 - Method for reshaping tubes and apparatus for making the same - Google Patents

Abstract

In a method of reshaping a tube (4), an apparatus is used which has a roller nip (10, 11) for rotating the tube (4), and a shaping roller assembly (12, 13) for alterning the cross-section of the tube (4), for instance from round to oval.

Description

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube deformation device and a method for tube deformation, in particular in the case of helically wound tubes with a connection seam for ventilation ducts.

BACKGROUND OF THE INVENTION

WO-A-99/51371 discloses a device, referred to as an ovalizer or oval-shaped device, which is intended to reshape a circular duct to oval, i.e. a device for changing the cross-section of a tube from a circular to oval. The tube is in particular a spiral channel tube, which is also referred to in the art as a helical coil tube.

In order to achieve such deformation of the pipe, the device is provided with a longitudinal horizontal assembly for forming a duct with two duct forming members which are spaced apart from each other in a vertical direction. These two channel forming members

The conduits are connected to one another by means of driving means arranged to move the conduit forming members relative to and away from each other in the vertical direction.

The annular tube to be reshaped is placed on the duct formation assembly, after which the drive means (several hydraulic cylinders) are actuated. As the distance between the duct forming members increases, they press on the inner surface of the tube at two opposite locations, the tube being deformed to an oval cross section. Each conduit forming member has a semicircular head that presses against the inner surface of the tube.

However, this known device suffers from certain drawbacks which will now be described below.

Firstly, due to the pressure applied to the interior of the pipe, the wall of the pipe is deformed and its material is expanded. This expansion can lead to cracking or other defects in the pipe wall.

Secondly, if the pipe is a helically wound pipe with a joint seam, as is the usual case, the pressing action may lead to slippage in the joint seam, which may further result in the formation of a pipe with different dimensions at each end. This can cause difficulties in connecting the pipes in the ventilation duct system.

Thirdly, the semicircular heads of the duct forming members must be replaced for each pipe diameter. This swapping operation is time-consuming, and several duct heads must be provided in stock. This leads to increased costs.

Fourthly, the known apparatus has a very low adaptability, since it can only be used to reshape from a circular to an oval shape.

Fifth, the deformed or reshaped oval shaped tube tends to return to its original circular shape due to the strain in the tube wall that is induced by deformation.

Therefore, there is a need for an improved tube deformation device.

Also known as bending machines is the prior art. The bending machine has a cylindrical assembly into which a metal plate or sheet is fed and formed into a desired shape, for example a circular cross-section. In the final step, the tube is sealed by a longitudinal weld along the tube wall. However, these bending machines cannot be used to reshape a tube, for example from a circular to an oval shape, since the starting material is always a flat plate or sheet.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new and improved technique for reshaping tubes, in particular helically wound tubes with a seam for

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ventilation ducts in order to overcome or at least alleviate the above drawbacks.

This object has been achieved by the development of a pipe deformation device having a circumferential wall, an outer surface, an inner surface, a longitudinal axis and a cross-section having at least one radius of curvature, the device comprising:

means arranged to rotate the tube about its longitudinal axis in the device, a first forming roller parallel to the longitudinal axis of the tube and configured to abut the outer surface of the tube, a second forming roller parallel to the longitudinal axis of the tube and configured to abut the inner surface of the tube; means arranged to move the first and second forming rolls relative to each other and relative to the rotating means in order to exert bending forces on the wall of the tube to effect change of said at least one radius of curvature and thereby to reshape the cross-section of the tube.

The shaping rollers and movement means are preferably arranged to exert bending forces at points of contact with the pipe wall which is spaced from the periphery of the pipe wall.

The forming rolls are preferably arranged to exert bending forces along the forming lines of the tube.

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Preferably, the pivot means comprises a clamping cylindrical assembly having two opposed cylinders configured to abut the tube wall disposed in the gap between the rollers and to provide driven rotation of the tube about its longitudinal axis.

The forming rolls are preferably parallel to the rolls of said cylindrical clamping assembly.

Preferably, the apparatus of the present invention further comprises a frame with two opposed and spaced apart frame members between which a tube is placed in operation, each frame member having guide means to which the end portions of the forming rolls are attached and which are arranged to effect said movement of the forming rolls.

The guide means are preferably grooves formed in the frame members in which the end portions of the forming rolls are received.

The actuating means are preferably arranged between the end portions of the forming rolls and said frame members.

The actuating means are preferably hydraulic cylinders.

The movement means preferably comprise arms connected to the end portions of the forming rolls and rotatable in a plane substantially perpendicular to the longitudinal axis of the tube.

The control means are preferably arranged between the arms and the frame members of the device.

The driving means are preferably hydraulic cylinders.

Advantageously, the apparatus of the invention further comprises an additional forming roll arranged to abut the outer surface of the tube and spaced from the first forming roll with respect to the circumference of the tube wall.

The additional forming roller and the first forming roller are preferably located on each side of the outer nip roller contained in the means for rotating the tube about its longitudinal axis.

In accordance with another aspect of the present invention, there is also provided a method of reshaping a tube having an outer surface, an inner surface, a longitudinal axis and a cross section having at least one radius of curvature, the method comprising the following steps:

rotating the tube about its longitudinal axis, and applying bending forces to the inner and outer surfaces of the tube, thereby varying said at least one radius of curvature to reshape the cross-section of the tube.

Preferably, the bending forces are exerted at the points of action on the pipe wall, the points of action being spaced from the circumference of the pipe wall.

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Preferably, the bending forces are moved along the circumference of the tube wall during tube deformation.

The bending forces are preferably applied along the forming lines of the pipe.

In accordance with yet another aspect of the present invention, there is also provided a cylindrical tube deformation unit having a cross-section and a longitudinal axis, said cylindrical unit comprising:

a first cylindrical assembly configured to rotate the tube about a longitudinal axis, a second cylindrical assembly configured to exert bending forces on the pipe directed toward or away from the pipe to vary the cross-section of the pipe.

In accordance with yet another aspect of the present invention, there is also provided the use of a cylindrical arrangement for reshaping a tube that rotates, wherein at least one forming roller is located within the tube while at least one forming roller is located outside the tube.

With the apparatus of the present invention, the problems of the prior art have been solved. Thanks to the sophisticated arrangement of the forming rolls and the means for moving them, the tube can be deformed very easily. The tube material is not stretched since the circumference of the tube does not change during the reshaping operation. As a result, there are no defects in the tube wall.

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In addition, the present apparatus can be used to reshape a large number of tubes, from circular to oval, from oval to circular, etc. In principle, any cross-sectional shape of the tube can be achieved as long as it has rounded corners such as triangular, rectangular and the like. The operation of the device according to the invention is therefore highly adaptable.

Another very significant advantage is that the same device can be used for all dimensions. No tube forming members need to be replaced if tubes of different sizes are to be reshaped. The same cylindrical arrangement can be used for all dimensions. This is indeed a great advantage over the device of WO-A-99/51371 discussed in the introduction.

In a preferred embodiment, the forming rolls are arranged to exert bending forces at points of action which are spaced from the circumference of the tube wall. As a result, a very smooth deformation operation can be achieved.

The forming rolls are preferably arranged to exert bending forces along the forming lines of the tube, thereby further improving the deformation operation.

Advantageously, the rotating means comprises clamping rollers, which are two opposing rollers arranged to abut the tube wall in the gap between the rollers and rotatably drive the tube about its longitudinal axis. Such clamping rollers ensure a safe and smooth rotating operation.

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The forming rolls and the nip rolls are preferably parallel for the simple control of the deformation operation. Moreover, the construction of the device is thus very compact by means of this arrangement.

In a preferred embodiment, the present apparatus comprises a frame with two opposing and spaced members between which a tube is positioned in operation. Each frame member has guide means to which the end portions of the forming rolls are attached and which are arranged to effect said movement of the forming rolls. These guide means in the frame members provide very good control of the movement of the forming rolls during the deformation. There is no disadvantageous inertia.

The guide means are preferably grooves formed in respective frame members.

In addition, it is preferred that the actuating or driving means, such as hydraulic cylinders, are arranged between the end portions of the forming rollers and the frame members. As a result, a very specific movement of the forming rolls is achieved.

In accordance with one aspect of the present invention, there is also provided a cylindrical tube deformation unit having a cross-section and a longitudinal axis, the cylinder unit comprising:

a first cylindrical assembly configured to rotate the tube about the longitudinal axis;

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a second cylindrical assembly configured to exert bending forces on the pipe directed towards or away from the pipe to vary the cross-section of the pipe.

The aforementioned objects of the present invention have also been achieved by developing a method for reshaping tubes.

The advantages of the process of the present invention, as well as its preferred variants, are substantially the same as the advantages and variants already described above with respect to the present device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail by way of examples of specific embodiments thereof, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a device according to a first embodiment of the present invention;

Figures 2, 3 and 4 are side elevational views of the tube deformation mechanism of the device shown in Figure 1;

Fig. 5 shows the different positions of the rollers included in the tube deformation mechanism;

Figures 6, 7 and 8 are side views of an alternative embodiment of a tube deformation mechanism with an additional cylinder;

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Figure 9 is a perspective view of a device according to a second embodiment of the present invention; and Figure 10 is a side elevational view of the tube deformation mechanism of the apparatus shown in Figure 9.

DETAILED DESCRIPTION OF THE INVENTION

1 to 5, the apparatus according to the first embodiment of the present invention comprises a frame 11 provided with two opposing and spaced frame members 2 and 3. A tube 6 having a wall 5, a circumference 6, an outer surface an inner surface 8 and a longitudinal axis C is disposed between these frame members 2 and 3.

The roll arrangement comprises two rotatable nip rollers 10 and 11 and two rotatable nip rollers 12 and 13. Rotatable nip rollers 10 and 11 provide means for forcibly rotating the tube 6 about its longitudinal axis C, while the rotatable forming rollers 12 and 13 provide for deformation of the tube 6, which will be described in more detail below.

The pipe 4 shown in connection with this exemplary embodiment is a helically wound pipe with a connection seam, made of sheet metal, suitable for ventilation ducts.

All the rollers 10 to 13 are parallel to each other and are also parallel to the longitudinal axis C of the pipe 4.

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The rotatable nip rollers 10 and 11 are driven by a motor M embedded in the frame 11, as shown schematically in FIG. 1.

A mounting assembly is provided on each frame member 2 and 3 for connecting the ends of the individual rollers 10 to 13 to the respective frame member 2 and 3. Only one mounting assembly is shown in FIG. 1.

This assembly comprises two arms 14 and 15 which are rotatably mounted on the frame member 3 at positions 14a and 15a, respectively, as shown in the figures of Figures 2 to 4.

The arm 14 is connected to the end shaft portion 12a of the rotary forming cylinder 12 inside the tube 4, the arm 15 being connected to the end shaft portion 13a of the rotary forming cylinder 13 outside the tube 4. The pivoting movement of the arms 14 and 15 (see double arrows) is carried out by means of control means, which are shown here as hydraulic cylinders 16 and 17, arranged on the frame member 3.

The upper rotary clamping cylinder 10 within the tube 4 is rotatably connected to the frame members 2 and 3 at its two end shaft portions 10a. However, this rotating clamping roller 10 is "stationary in the sense that it cannot move from its position in the frame 11".

However, the lower pivot nip roller 11 is movable vertically by means of the actuating means, which here are formed by a hydraulic roller 18 arranged on the frame member 3.

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Principles of operation of the tube deformation device are illustrated in Figures 2 to 5.

A tube 4 of circular cross-section is arranged in the device, rotating in a clockwise direction by means of the clamping rollers 10 and 11 clamping the wall 5 of the tube 6 therebetween. The inner or upper forming roller 12 abuts the inner surface 8 of the tube 4, while the outer or lower forming roller 13 abuts the outer surface 7 of the tube 4. The forming rolls 12 and 13 contact the wall 5 of the tube 4 along the forming lines G of the tube 4.

Due to the pivoting rotation of the arms 14 and 15, the shaping rollers 12 and 13 then exert bending forces on the wall 5 of the pipe 4 at points 19 and 21 of action which are spaced from the circumference 6 of the pipe 4. As a result, the forming rolls 12 and 13 move relative to each other and to the clamping rolls 10 and 11.

As a result of this action, the tube 4 can be shaped into an intermediate cross-sectional shape as shown in FIG. 3 and finally to a target oval cross-sectional shape as shown in FIG. 4.

In operation, the movement of the forming rolls 12 and 13 is precisely controlled by a computer (not shown). The mutual cooperation between the two shaping rollers 12 and 13 exerting said bending forces on the wall 5 of the tube 4 ensures a smooth deformation of the tube 4.

14 • • • ··· · *. • · t • · · · • · · · · • · · · «· ·· ·· ·· · • »« «· • · · · · · · · »*» * ·· ·· · First shaping cylinder 13 serves for shrinking radius R curvature tubing 4, while second shaping

the roller 12 serves to increase the radius R of the curvature of the tube 4. The outer forming roller 13 exerts bending forces which are substantially directed towards the center of the tube 4, while the inner forming roller 12 exerts bending forces directed outward from the center of the tube 4. In operation, the two forming rolls 12 and 13 cooperate with each other to provide a suitable bending action.

The arms 14 and 15 are preferably rotatable in a plane P which is perpendicular to the longitudinal axis C of the pipe 4.

The respective end positions of the shaping rollers 12 and 13 are shown by dashed lines in FIG. 5. These end positions may, of course, vary depending on the desired final shape of the tube 4.

In this exemplary embodiment, it is shown how the circular tube 4 is formed into an oval tube, that is, the radius R of the curvature of the tube 4 varies. However, the present apparatus can also be used for shaping an oval tube into a circular tube and the like. There are no particular limitations in terms of deformation with respect to the initial or final cross-section of the pipe 4.

As shown in FIG. 1, the frame member 3 is rotatably mounted at 21 so that this portion of the frame 1 can be opened to receive the tubes in the apparatus and to remove the reshaped tubes from the apparatus. It will be understood that the inner nip rollers 10 and 12 must be detached from their receptacles if the tube 6 is to be inserted into or removed from the apparatus.

The number of rollers is not decisive when the tubes are reshaped.

An alternative exemplary embodiment is shown in the figures of Figures 6 to 8.

The rollers 10 to 13 are the same as in the above embodiment, but an additional outer forming roller 22 is added here. Since the additional outer forming roller 22 and the outer forming roller 13 are located on each side of the outer nip roller 11, a very smooth roller can be achieved. and efficient pipe reshaping operations.

By raising and lowering the two forming rollers 13 and 22 in a precisely defined (computer controlled) order, a very advantageous reshaping is achieved.

A second embodiment of the device according to the invention is shown in the figures of Figures 9 to 10.

The main difference between this second embodiment and the above-described first embodiment relates to the means for gripping the rollers 10-13 and for moving them. The device according to FIGS. 9 to 10 has two assemblies of mounting means, one at each end. Only one system will be described in the following description.

The end shaft portion 11a of the outer nip roller 11 is mounted in a longitudinal slot or groove 23 in the frame member 3, wherein the end shaft portion 13a of the outer nipple is mounted in a longitudinal slot or groove 23 in the frame member.

The forming roller 13 is mounted in a longitudinal slot or groove 24 in the frame member 3.

These grooves 23 and 24 represent means for guiding the movement of the associated cylinders 11 and 13 by means of the control means, which, as in the first embodiment, are hydraulic cylinders 18 and 17. The shape of the grooves 23 and 24 must be calculated relative to the desired movement and operation . Normally the grooves 23 and 24 are linear but may also have a slightly curved shape (not shown).

As in the first embodiment, the outer or lower nip roller 11 is movable vertically, while the inner or upper nip roller 10 is "stationary, but understandably rotatable." Inner forming roller. 12 and the outer forming roller 13 are movable in directions that are at an angle to the vertical movement of the lower nip roller 11. In the illustration of FIG.

The somewhat modified hydraulic cylinder 16 'is connected to the end shaft portion 12a of the inner forming cylinder 12. The difference from the hydraulic cylinder 16 shown in Figure 1 is that the modified hydraulic cylinder 16' is removably attached to the As a result, the modified hydraulic cylinder 16 'can be removed from the forming cylinder 12 and pivoted to a vertical position around the pivot pin 26, allowing the tube 4 to be replaced.

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If the tube 6 is to be placed between or removed from the nip rollers 10 and 11, the nip roll 11 is lowered by the hydraulic cylinder 18, the nip 25 is removed from the end shaft portion 12a, and the hydraulic cylinder 16 'is pivoted to its vertical position.

As with the embodiment of FIG. 1, the frame member 3 is pivotable at 21 so that this portion of the frame can be opened.

Preferably, the hydraulic cylinders 16 ', 17 and 18 are located substantially in a common plane that is perpendicular to the longitudinal axis C of the tube 6. This results in a very compact and reliable construction.

In order to achieve smooth movement of the inner forming cylinder 12, its end shaft portion 12a is connected to the end shaft portion 10a via a coupling member 27. This coupling member 27 also serves to hold the upper nip roller 10 when the tube 4 is removed from the nip rollers 10 and 11. .

As in the first embodiment, the first forming roller 13 reduces the radius of curvature, while the second forming roller 12 increases this radius of curvature. In Figure 10, the inner forming roller 12 is shown in its highest position above the nip rollers 10 and 11, but the forming roller 12 can be lowered in the direction of the hydraulic cylinder 16 'to a position in which it exerts bending forces on the wall 2 of the tube 4. in cooperation with the outer forming cylinder 13. Then the hydraulic cylinder 16 'is rotated around the pivot pin 26.

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Very good practical results have been achieved with the aid of the present device. The helical coil seams for use in the ventilation duct have been successfully reshaped from a circular shape to an oval shape without the drawbacks of the prior art, as already mentioned in the introduction.

A simple and improved method for reshaping tubes has been developed in accordance with the present invention. It is particularly advantageous that the circumference of the tube remains unchanged during the deformation.

Finally, it is to be understood that the present invention is by no means limited to the embodiments described above, as many modifications may be made within the spirit and scope of the invention as defined in the appended claims.

It should be noted, for example, that a number of rollers other than those described above may be used, and the present invention is not limited to any particular type of tube.

In addition, other actuating or driving means other than hydraulic cylinders can be used, for example pneumatic cylinders, electrically driven units (linear units) and the like.

Alternative means may also be employed to provide rotation, assembly and movement of the rollers.

For example, the hydraulic cylinder 18 providing movement of the nip roller 11 may be replaced by a unit

(Not shown), comprising an axially driven roller that moves the nip roller 11 up and down via a wedge assembly.

In addition, the hydraulic cylinder 16 'and the clamping member or jaw 25 providing movement of the forming cylinder 12 may be replaced by a ring gear unit (not shown) attached to the forming cylinder 12 or its end shaft portion 12a. By rotating the ring gear, the forming roller 12 moves along a sector of the circle as shown by the double arrows in the figures of Figures 5 to 8. The ring gear is driven by suitable means, preferably electrically driven. With this ring gear unit, the shaping roller 12 can perform a pivoting movement between two end positions, for example along a semicircle.

Claims (20)

PATENT CLAIMS A device for reshaping a pipe (4), the pipe (4) having a wall (5) with a perimeter (6), an outer surface (7), an inner surface (8), a longitudinal axis (C) and a cross section having at least one radius (R) a curvature comprising: means (10, 11) arranged to rotate the tube (4) about its longitudinal axis (C) in the device, a first forming roller (13) parallel to the longitudinal axis (C) of the tube (4) and arranged to abut the outer surface ( 7) a tube (4), a second forming roller (12) parallel to the longitudinal axis (C) of the tube (4) and arranged to abut the inner surface (8) of the tube (4), and means (14, 15, 16, 17) 18) configured to move the first and second forming rolls (12, 13) relative to each other and relative to the rotating means (10, 11) to exert bending forces on the wall (5) of the tube (4) to effect a change of at least one radius of curvature (R) and thus for deforming the cross-section of the pipe (4). Apparatus according to claim 1, characterized in that the shaping rollers (12, 13) and the movement means (14, 15, 16, 17, 18) are arranged to exert bending forces at the points (19, 18). 20) acting on a pipe wall (5) which is spaced from the circumference (6) of the pipe wall (5). Device according to Claim 2 or Claim 2, characterized in that the rollers (12, 13) are arranged to exert bending forces along the generating lines (G) of the tube (4). Apparatus according to any one of the preceding claims, characterized in that the rotating means comprises a clamping cylindrical assembly having two opposing rollers (10, 11) arranged to abut against a wall (5) of the tube (4) disposed in the gap between the rollers (4). 10, 11), and to provide driven rotation of the pipe (4) about its longitudinal axis (C). according to claim 4, characterized in that said forming means are parallel to said rollers (10, 11) A device identifying the cylinders (12, 13) of the cylindrical clamping assembly. A device according to any one of the preceding claims, further comprising a frame (1) with two opposing and spaced apart frame members (2, 3) between which a tube (4) is disposed in operation, the frame member (2, 3) is provided with guiding means (24, 16 ', 27) to which the end portions (12a, 13a) of the forming rollers (12, 13) are connected and which are arranged to effect said movement of the forming rollers (12). 12, 13). · * · · · · · · · «« Device according to claim 6, characterized in that the guide means are grooves (24) provided in the frame members (2, 3) in which the end portions of the forming rollers are received. Device according to claim 6 or 7, characterized in that the control means (16, 17) are arranged between the end portions (12a, 13a) of the forming rolls (12, 13) and said frame members (2, 3). Device according to claim 1, characterized in that the means are hydraulic cylinders (16, 17). 8, control Device according to claim 1, characterized in that the movement means comprise arms (14, 15) connected to the end portions (12a, 13a) of the forming rolls (12, 13) and rotatable in a plane (P) which is substantially perpendicular on the longitudinal axis (C) of the pipe (4). Device according to claim 10, characterized in that the control means (16, 17) are arranged between the arms (14, 15) and the frame members (2, 3) of the device. Device according to claim 1, characterized in that the means are hydraulic cylinders (16, 17). 11, driving • · · ··· · · ···· - · · · 4 · · · The apparatus of claim 1, further comprising an additional forming roller (22) arranged to abut the outer surface (7) of the tube (4) and spaced from the first forming roller (13) with respect to the circumference (6). ) the wall (5) of the pipe (4). Apparatus according to claim 13, characterized in that the additional forming roller (22) and the first forming roller (13) are located on each side of the outer nip roller (11) contained in the means (10, 11) for rotating the tube (4). ) about its longitudinal axis (C). A method of reshaping a pipe (4), the pipe (4) having an outer surface (7), an inner surface (8), a longitudinal axis (C) and a cross section having at least one radius of curvature (R), comprising next steps: rotating the tube (4) about its longitudinal axis (C), and exerting bending forces on the inner and outer surfaces (8), 7) a pipe (4), and thereby varying said at least one radius of curvature (R) to reshape the cross-section of the pipe (4). 16. The method according to claim 15, characterized in that the bending forces are generated at locations (19, 20) acting on a wall (5) »· ·· ··, ϊ · · · · ♦ •> ¹ · · ·» · • · ♦ · «». * ,,,, • · · · · · Λ Λ Λ. Λ. - tubes (4), the points of action being spaced from the circumference (6) of the wall (5) of the tube (4). Method according to claim 16, characterized in that the bending forces are moved along the circumference (6) of the wall (5) of the tube (4) during the deformation of the tube (4). Method according to claim 15, characterized in that the bending forces are exerted along the forming lines (G) of the pipe (4). A roller unit for deforming a tube (4) having a cross-section and a longitudinal axis (C), characterized in that it comprises: a first cylindrical assembly (10, 11) arranged to rotate the pipe (4) about the longitudinal axis (C), a second cylindrical assembly (12), exerting bending forces on the pipe towards the pipe (4) or away from the pipe pipe (4). 13) arranged for (4) oriented in the direction (4) for changing the cross-section Use of a cylindrical arrangement for reshaping a tube (4) that rotates, wherein at least one forming roller (12) is located inside the tube (4) while at least one forming roller (13) is located outside the tube (4).